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A248583 The least number m == 1 (mod 6) that is divisible by prime(n). 0
25, 7, 55, 13, 85, 19, 115, 145, 31, 37, 205, 43, 235, 265, 295, 61, 67, 355, 73, 79, 415, 445, 97, 505, 103, 535, 109, 565, 127, 655, 685, 139, 745, 151, 157, 163, 835, 865, 895, 181, 955, 193, 985, 199, 211, 223, 1135, 229, 1165, 1195, 241, 1255, 1285, 1315, 1345, 271, 277, 1405, 283, 1465, 307 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,1

COMMENTS

If a(n) is not prime then a(n)=5*prime(n).

LINKS

Table of n, a(n) for n=3..63.

FORMULA

a(n) = (4*floor((mod(prime(n),6)+4)/6)+1)*prime(n). - Farideh Firoozbakht, Oct 09 2014

EXAMPLE

a(3)=25 because p=prime(3)=5 and  25= 5*5=1+4*6

a(5)=55 because p=prime(5)=11 and  55= 11*5=1+9*6

a(200)=6115 because p=prime(200)=1223 and 6115=1223*5=1+1019*6.

MATHEMATICA

Table[ChineseRemainder[{0, 1}, {Prime[n], 6}], {n, 3, 200}]

(*or*)Table[p = Prime[n]; If[Mod[p, 6] > 1, 5*p, p], {n, 3, 200}]

Table[p=Prime[n]; (4Floor[(Mod[p, 6]+4)/6]+1)*p, {n, 3, 63}](* Farideh Firoozbakht, Oct 09 2014 *)

CROSSREFS

Cf. A002476, A016921.

Sequence in context: A245631 A243092 A126837 * A080203 A040605 A307179

Adjacent sequences:  A248580 A248581 A248582 * A248584 A248585 A248586

KEYWORD

nonn

AUTHOR

Zak Seidov, Oct 09 2014

STATUS

approved

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Last modified January 28 12:46 EST 2022. Contains 350656 sequences. (Running on oeis4.)